Dominoes (or dominos) is a game played with rectangular "domino" tiles. The domino gaming pieces make up a domino set, sometimes called a deck or pack. The traditional Sino-European domino set consists of 28 dominoes, colloquially nicknamed bones, cards, tiles, tickets, stones, or spinners. Each domino is a rectangular tile with a line dividing its face into two square ends. Each end is marked with a number of spots (also called pips, nips or dobs) or is blank. The backs of the dominoes in a set are indistinguishable, either blank or having some common design. A domino set is a generic gaming device, similar to playing cards or dice, in that a variety of games can be played with a set.

The earliest mention of dominoes is from Song Dynasty China, found in the text Former Events in Wulin.[1] Dominoes first appeared in Italy during the 18th century, and although it is unknown how Chinese dominoes developed into the modern game, it is speculated that Italian missionaries in China may have brought the game to Europe.[2]

The name "domino" is from the resemblance to a kind of hood worn during the Venice carnival.[3][4]

European-style dominoes are traditionally made of bone such as ivory, or a dark hardwood such as ebony, with contrasting black or white pips (inlaid or painted). Alternatively, domino sets have been made from many different natural materials: stone (e.g., marble, granite or soapstone); other hardwoods (e.g., ash, oak, redwood and cedar); metals (e.g., brass or pewter); ceramic clay, or even frosted glass or crystal. These sets have a more novel look, and the often heavier weight makes them feel more substantial, but such materials and the resulting products are usually much more expensive than polymer materials.

Domino tiles

Modern commercial domino sets are usually made of synthetic materials, such as ABS or polystyreneplastics, or Bakelite and other phenolic resins; many sets approximate the look and feel of ivory while others use colored or even translucent plastics to achieve a more contemporary look. Modern sets also commonly use a different color for the dots of each different end value (one-spots might have black pips while two-spots might be green, three red, etc.) to facilitate finding matching ends. Occasionally, one may find a domino set made of card stock like that for playing cards. Such sets are lightweight, compact and inexpensive, but like cards are more susceptible to minor disturbances such as a sudden breeze. Sometimes dominoes have a metal pin (called a spinner or pivot) in the middle.[5]

The traditional set of dominoes contains one unique piece for each possible combination of two ends with zero to six spots, and is known as a double-six set because the highest-value piece has six pips on each end (the "double six"). The spots from one to six are generally arranged as they are on six-sided dice, but because there are also blank ends having no spots there are seven possible faces, allowing 28 unique pieces in a double-six set.

However, this is a relatively small number especially when playing with more than four people, so many domino sets are "extended" by introducing ends with greater numbers of spots, which increases the number of unique combinations of ends and thus of pieces. Each progressively larger set increases the maximum number of pips on an end by three, so the common extended sets are double-nine, double-twelve, double-fifteen and double-eighteen. Larger sets such as double-twenty-one can theoretically exist but are rarely seen in retail stores, as identifying the number of pips on each domino becomes difficult, and a double-twenty-one set would have 253 pieces, far more than is normally necessary for most domino games even with eight players.

The oldest confirmed written mention of dominoes in China comes from the Former Events in Wulin (i.e. the capital Hangzhou) written by the Yuan Dynasty (1271–1368) author Zhou Mi (1232–1298), who listed "pupai" (gambling plaques or dominoes) as well as dice as items sold by peddlers during the reign of Emperor Xiaozong of Song (r. 1162–1189).[1] Andrew Lo asserts that Zhou Mi meant dominoes when referring to pupai, since the Ming author Lu Rong (1436–1494) explicitly defined pupai as dominoes (in regards to a story of a suitor who won a maiden's hand by drawing out four winning pupai from a set).[1]

The earliest known manual written about dominoes is the 《宣和牌譜》(Manual of the Xuanhe Period) written by Qu You (1341–1437).[1] But some Chinese scholars believe this manual is a forgery from a later time.[6]

In the Encyclopedia of a Myriad of Treasures, Zhang Pu (1602–1641) described the game of laying out dominoes as pupai, although the character for pu had changed, yet retained the same pronunciation.[1] Traditional Chinese domino games include Tien Gow, Pai Gow, Che Deng, and others. The thirty-two-piece Chinese domino set, made to represent each possible face of two thrown dice and thus have no blank faces, differs from the twenty-eight-piece domino set found in the West during the mid 18th century.[7]

Many different domino sets have been used for centuries in various parts of the world to play a variety of domino games. Each domino originally represented one of the 21 results of throwing two 6-sided dice (2d6). One half of each domino is set with the pips from one die and the other half contains the pips from the second die. Chinese sets also introduce duplicates of some throws and divide the dominoes into two classes: military and civil. Chinese dominoes are also longer than typical European dominoes.

The early 18th century witnessed dominoes making their way to Europe, making their first appearance in Italy. The game changed somewhat in the translation from Chinese to the European culture. European domino sets contain neither class distinctions nor the duplicates that went with them. Instead, European sets contain seven additional dominoes, with six of these representing the values that result from throwing a single die with the other half of the tile left blank, and the seventh domino representing the blank-blank (0–0) combination.

Ivory Dominoes were routinely used in 19th century rural England in the settling of disputes over traditional grazing boundaries, and were commonly referred to as "bonesticks" (see Hartley, Land Law in West Lancashire in the mid- 19th Century, Farm Gazette, March 1984).

Domino tiles, also known as bones, are twice as long as they are wide and usually have a line in the middle dividing them into two squares. The value of either side is the number of spots or pips. In the most common variant (Double Six) the values range from blank or 0 (no pips) to 6.[8] The sum of the two values, i.e. the total number of pips, may be referred to as the rank or weight of a tile, and a tile with more pips may be called heavier than a lighter tile with fewer pips.

Tiles are generally named after their two values; e.g. 2–5 or 5–2 are alternative ways of describing the tile with the values 2 and 5. Tiles that have the same value on both ends are called doubles, and are typically referred to as double-zero, double-one etc.[8] Tiles with two different values are called singles.[9]

Every tile belongs to the two suits of its two values, e.g. 0–3 belongs both to the blank suit (or 0 suit) and to the 3 suit. Naturally the doubles form an exception in that each double belongs to only one suit.[8] In 42, the doubles are treated as an additional suit of doubles, so that, e.g., the double-six 6–6 belongs both to the 6 suit and the suit of doubles.

The most common domino sets commercially available are Double Six (with 28 tiles) and Double Nine (with 55 tiles). Larger sets exist and are popular for games involving several players or for players looking for long domino games. The number of tiles in a set has the formula for a double- set.[10]

The most basic domino variant is for two players and requires a double six set. The 28 tiles are shuffled face down and form the stock or boneyard. Each player draws seven tiles; the remainder are not used. Once the players begin drawing tiles, they are typically placed on-edge before the players, so that each player can see his own tiles, but none can see the value of other players' tiles. Every player can thus see how many tiles remain in the other players' hands at all times during gameplay. One player begins by downing (playing the first tile) one of their tiles. This tile starts the line of play, a series of tiles in which adjacent tiles touch with matching, i.e. equal, values. The players alternately extend the line of play with one tile at one of its two ends. The game ends when one player wins by playing their last tile, or when the game is blocked because neither player can play. If that occurs, whoever caused the block gets all of the remaining player points not counting their own.[8]

Players accrue points during game play for certain configurations, moves, or emptying one's hand. Most scoring games use variations of the draw game. If a player does not call "domino" before the tile is laid on the table, and another player says 'domino' after the tile is laid, the first player must pick up an extra domino. In "Mexican train" the double zero domino is scored as 7 points.

In a draw game (blocking or scoring), players are additionally allowed to draw as many tiles as desired from the stock before playing a tile, and they are not allowed to pass before the stock is (nearly) empty.[8] The score of a game is the number of pips in the losing player's hand plus the number of pips in the stock. Most rules prescribe that two tiles need to remain in the stock.[9] The Draw game is often referred to as simply "dominoes".[11]

Adaptations of both games can accommodate more than two players, who may play individually or in teams.[8]

Muggins played with multi-colored tiles. The doubles serve as spinners, allowing the line of play to branch.

The line of play is the configuration of played tiles on the table. It starts with a single tile and typically grows in two opposite directions when players add matching tiles. In practice, players often play tiles at right angles when the line of play gets too close to the edge of the table.

The rules for the line of play often differ from one variant to another. In many rules, the doubles serve as spinners, i.e., they can be played on all four sides, causing the line of play to branch. Sometimes the first tile is required to be a double, which serves as the only spinner.[9] In some games such as Chicken Foot, all sides of a spinner must be occupied before anybody is allowed to play elsewhere. Matador has unusual rules for matching. Bendomino uses curved tiles, so that one side of the line of play (or both) may be blocked for geometrical reasons.

In Mexican Train and other train games, the game starts with a spinner from which various trains branch off. Most trains are owned by a player and in most situations players are allowed to extend only their own train.

In blocking games, scoring happens at the end of the game. After a player has emptied his hand, thereby winning the game for their team, the score consists of the total pip count of the losing teams' hands. In some rules, the pip count of the remaining stock is added. If a game is blocked because no player can move, the winner is often determined by adding the pips in players' hands.[9]

In scoring games, each individual can potentially add to the score. For example, in Bergen, players score 2 points whenever they cause a configuration in which both open ends have the same value and 3 points if additionally one open end is formed by a double.[12][13] In Muggins, players score by ensuring the total pip count of the open ends is a multiple of a certain number. In variants of Muggins, the line of play may branch due to spinners.

In British public houses and social clubs, a scoring version of "5s-and-3s" is used. The game is normally played in pairs (two against two) and is played as a series of "ends". In each "end", the objective is for players to attach a domino from their hand to one end of those already played so that the sum of the end dominoes is divisible by 5 or 3. One point is scored for each time 5 or 3 can be divided into the sum of the two dominoes i.e. four at one end and 5 at the other makes 9, which is divisible by 3 three times, resulting in 3 points. Double 5 at one end and 5 at the other makes 15 which is divisible by 3 five times (5 points) and divisible by 5 three times (3 points) for a total of 8 points.

An "end" stops when one of the players is out, i.e., has played all of his dominoes. In the event no player is able to empty his hand, then the player with the lowest domino left in hand is deemed to be 'out' and scores one point. A game consists of any number of "ends" with points scored in the "ends" accumulating towards a total. The game ends when one of the pairs' total score exceeds a set number of points. A running total score is often is kept on a cribbage board. 5s-and-3s is played in a number of competitive leagues in the British Isles.

In many versions of the game, the player with the highest double leads with that double, for example "double six". If no one has it, the next highest double is called: "double five?", then "double four?", etc. until the highest double in any of the players hands is played. If no player has an "opening" double, the next heaviest domino in the highest suit is called - "six - five?", "six - four?". In some variants, players take turns picking dominoes from the stock until an opening double is picked and played. In other variants, the hand is reshuffled and each player picks seven dominoes. After the first hand, the winner (or winning team) of the previous hand is allowed to pick first and begins by playing any domino in his or her hand.

Playing the first bone of a hand is sometimes called setting, leading, downing, or posing the first bone. Dominoes aficionados often call this procedure smacking down the bone. After each hand, bones are shuffled and each player draws the number of bones required, normally seven. Play proceeds clockwise. Players in turn must play a bone with an end that matches one of the open ends of the layouts.

In some versions of the games, the pips or points on the end, and the section to be played next to it must add up to a given number. For example, in a double six set the "sum" would be six, requiring a "blank" to be played next to a "6," a "1" next to a "5", a "2" next to a "4", etc.

The stock of bones left behind, if any, is called the bone yard, and the bones therein are said to be sleeping. In draw games, players take part in the bone selection, typically drawing from the bone yard when they don't have a "match" in their hand.

If a player inadvertently picks up and sees one or more extra dominoes, those dominoes becomes part of his or her hand.

A player who can play a tile may be allowed to pass anyway. Passing can be signalled by tapping twice on the table or by saying "go" or "pass".

Play continues until one of the players has played all the dominoes in his or her hand, calls "Out!", "I win", or "Domino!" and wins the hand, or until all players are blocked and no legal plays remain. This is sometimes referred to as lock down or "sewed up". In a common version of the game, the next player after the block picks up all the dominoes in the bone yard as if trying to find a (non-existent) match. If all the players are blocked, or locked out the player with the lowest hand (pip count) wins. In team play, the team with the lowest individual hand wins. In the case of a tie, the first of tied players or the first team in the play rotation wins.

In games where points accrue, the winning player scores a point for each pip on each bone still held by each opponent or the opposing team. If no player went out, the win is determined by the lightest hand, sometimes only the excess points held by opponents.

A game is generally played to 100 points, the tally being kept with paper and pencil. In more common games, mainly urban rules, games are played to 150, 200, or 250 points.

In some games the tally is kept by creating houses, where the beginning of the house (the first ten points) is a large +, the next ten points are O, and scoring with a 5 is a /, and are placed in the four 'corners' of the house.

In some versions, if a lock down occurs, the first person to call a lock-down gains the other players bones and adds the amount of the pips to their house. If a person who calls rocks after a call of 'lock-down' or 'domino' finds the number of pips a player called is incorrect, those points become his.

Apart from the usual blocking and scoring games, there are also domino games of a very different character, such as solitaire or trick-taking games. Most of these are adaptations of card games and were once popular in certain areas to circumvent religious proscriptions against playing cards.[14] A very simple example is a Concentration variant played with a double-six set; two tiles are considered to match if their total pip count is 12.

A popular domino game in Texas is 42. The game is similar to the card game spades. It is played with four players paired into teams. Each player draws seven dominoes, and the dominoes are played into tricks. Each trick counts as 1 point, and any domino with a multiple of 5 dots counts toward the total of the hand. 35 points of "five count" + 7 tricks = 42 points, hence the name.

Dominoes is played at a professional level, similar to poker. Numerous organisations and clubs of amateur domino players exist around the world. Some organizations, including the Fédération Internationale de Domino (FIDO)[1], organize international competitions. The 2008 and 2009 Double FIDO domino world champion from the UK is Darren Elhindi.

Besides playing games, another use of dominoes is the domino show, which involves standing them on end in long lines so that when the first tile is toppled, it topples the second, which topples the third, etc., resulting in all of the tiles falling. By analogy, the phenomenon of small events causing similar events leading to eventual catastrophe is called the domino effect.

Arrangements of millions of tiles have been made that have taken many minutes, even hours to fall. For large and elaborate arrangements, special blockages (also known as firebreaks) are employed at regular distances to prevent a premature toppling from undoing more than a section of the dominoes while still being able to be removed without damage.

The Netherlands has hosted an annual domino toppling exhibition called Domino Day since 1986. The event held on 18 November 2005 knocked over 4 million dominoes by a team from Weijers Domino Productions. On Domino Day 2008 (14 November 2008), the Weijers Domino Productions team attempted to set 10 records:[17][18]

Since April 2008,[19] the character encoding standard Unicode includes characters that represent the double-six domino tiles in various orientations. All combinations of 0 through 6 pips on the left or right provides 7x7 or 49 glyphs, the same combinations vertically for another 49, and also a horizontal and a vertical "back" for a total of 100 glyphs. In this arrangement, both orientations are present: horizontally both tiles [1|6] and [6|1] exist, while a regular game set only has one such tile. The Unicode range for dominoes is U+1F030–U+1F09F. The naming pattern in Unicode is, by example, U+1F03B🀻domino tile horizontal-01-03. Few fonts are known to support these glyphs.[20]

^" A domino is a kind of hood worn by the canons of a cathedral church. Later the name was given to a mourning-veil for women and later still to half-masks worn by women when travelling or at a masquerade, for disguise. A domino was a masquerade-dress worn for disguise by ladies and gentlemen, and consisting of an ample cloak or mantle with wide sleeves and a hood removable at pleasure. It was usually made of black silk, but sometimes of other colours and materials. " [The Probert Encyclopaedia]